os references: sheet 149 - start and finish 418192 start opposite "p" sign in lay by on unclassified road near cross ash (map ref. 50417193). turn left and proceed through cross ash on b4521 to signpost "wern goch lyn farm where turn left and left again onto b4233. great care through hairpin bends before turning left at rockfield to join b4347, through newcastle to finish opposite starting point.